Shock responsive mechanism



April 12,-1949. J. A. FAVRE 2,467,200

SHOCK RESPONS IVE MEGHANI SM Filed Feb. '7, 1948 TRIPPING DIRECTION T SHAFT O RCUIT BREAKER TRIPPI DIRE m T SHAFT 0 RCUIT BREAKER inventor: John A Favve,

His AttoTn ey.

Patented Apr. 12, 1949 SHOCK RESPONSIVE MECHANISM John A. Favre, Drcxel Hill, Pa., assignor to General Electric Company, a corporation of New York Application February 7, 1948, Serial No. 6,869

6 Claims.

My invention relates to improvements in shock responsive mechanisms and more particularly to mechanisms for preventing the false operation of devices in consequence of shocks without interfering with the intended operation of the devices longer than the duration of the shock.

Devices such as circuit breakers, relays and the like, which are intended to function under abnormal conditions of an electric circuit, are liable to operate falsely under shock conditions. On board warcraft, especially in time of battle, such shock produced false operations could prove extremely crucial by effecting the deenergization of motors and other apparatus so critically needed in operation. In order to prevent such false operations, various arrangements have been proposed and many actually used. Many of these arrangements materially interfere with or actually prevent the intended fault responsive operation of the devices since they either render the devices less sensitive in their fault responsive action or leave the devices indefinitely locked against operation. Other arrangements which do not materially interfere with the intended operation of the devices are either too dependent on the human element or else too complicated to apply to existing circuit breaker and relay structures.

An object of my invention is to provide for devices, and particularly protective devices such as circuit breakers, relays and the like, an improved shock responsive rotary pendulum mechanism for preventing false operation of the devices under shock conditions without interfering with the intended operation of the devices except to a limited degree during shock conditions. Another object of my invention is to provide a shock responsive mechanism involving an inverted pendulum weight mounted to have a universal conic rotary motion which functions automatically on the occurrence of a shock to prevent false operation of the device to which it is applied and which is automatically self-restoring to a central shock susceptible position upon the subsidence of the shock. A further object of my invention is to provide a relatively simple, automatic, shock responsive mechanism having a structure readily adaptable to existing protective devices such as circuit breakers, relays and the like. These and other objects of my invention will appear in more detail hereinafter.

In accordance with my invention, I provide for devices such, for example, as circuit breakers, relays and the like, for preventing the false operation thereof on the occurrence of shocks, a blocking element movable from an initial position into engagement with a part of the device to prevent a shock produced operation thereof. For effecting the preventing movement of the blocking element, I provide means comprising a support which is subject to shocks effecting the device and on which is mounted a weight for substantially universal movement relatively to the support. Between the weight and the blocking element, I provide a slip connection for permitting movement of each relatively to the other. Also in accordance with my invention, I provide yieldable force exerting means tending to maintain the weight in a predetermined shock susceptible position on the support and the blocking element in its initial position.

My invention will be better understood from the following description when considered in connection with the accompanying sheet of drawings, and its scope will be pointed out in the appended claims.

In the accompanying sheet of drawings, Fig. 1 is a vertical elevation, partly in section, of a shock responsive mechanism embodying my invention and shown in the normal or rest position; and Fig. 2 is a view similar to Fig. 1 showing the position of the parts in consequence of a shock having a force component from left to right as viewed in the drawing.

In the two figures of the drawing, I have illustrated an embodiment of my invention as applied to prevent or block the tripping action of a circuit breaker mechanism of which there is shown only the trip shaft I with an arm 2 rigidly secured thereto inasmuch as it will be obvious to those skilled in the art that my invention is not limited in its application to a particular circuit breaker or to circuit breakers but may be used to prevent shock produced false operation of other devices. As indicated in the drawing, the tripping direction of the trip shaft 1' is clockwise. The purpose of my invention is to prevent this tripping movement when it is induced by shocks affecting the circuit breaker.

In accordance with my invention, I prevent this shock induced false operation by a blocking element 3 which is movable from an initial position shown in Fig. 1 into engagement with the arm 2 to prevent a shock produced operation of the circuit breaker by blocking the clockwise movement of the trip shaft 1. As shown, the blocking element 3 is a bell crank having arms 4 and 5. This crank is pivotally mounted at 6 so that the arm 4 can be moved into abutting engagement with the arm 2 on the trip shaft l to prevent rotation of this shaft in the tripping dioverload devices to overcome the shock lock rection. restraint and trip the circuit breaker without For efiecting the preventive movement of the waiting for th oscillations of the weight to subblocking element 3, I provide, in accordance with side. my invention, a support 1 subject to shocks af- 5 A body free to rotate, even though supported by fecting the circuit breaker. As shown, the sup- 2. pin at its center of gravity, tends to turn when port 'I is a cup which is secured as by welding vibrated. If such a body is definitely positioned or otherwise to abase member 8. This base memby some projection bearing against a fixed pin, ber is mounted so as to partake of the shocks to any impact on the supporting structure will be which the circuit breaker is subjected. Thus, the transmitted to the body through both the supbase 8 may be suitably secured to the circuit portng and the positioning pin. This imp-act breaker frame, mounted rigidly within the cirthrough the fixed pin will produce higher angular cuit breaker housing or otherwise, as will be obacceleration if the positioning pin is rigid. This vious to those skilled in the art. occurs even though the direction of shock is at Mounted on the cup 1 for substantially uni- 5 right angles to the plane of rotation. Accordversal conic rotary movement relatively thereto ingly, although tie effective length of the rod I3 is a inverted pendulum Weight 9 having a b s between its head It and the nut l9 determines p r i n Iii seated in t p n the rest p i ion the initial or off position of the crank 3, I preff the W t Shown n e We g t 9 ay erably provide a stop which is positioned on be h a y o li ht depending on the amount of the base 5 for engagement by the arm i of the unbalance of the system to be blocked. The base crank upon clockwise movement thereof. In p ion I 0 of h w i t s o s p as to p mi order to give the bell crank 3 the maximum initial u r mov m nt o t w h l tiv ly t acceleration from the impact of shocks, this back the cup. Thus, in the illustrated embodiment t gg h ld be mad relatively rigid,

Of y invention, the inner Wall ii of the D 5 Referring now to Fig. 1 in which the parts are 7 s Substantially Cylindrical and t e inside shown in the normal or rest position, that is, no b ttOm su fa l of t e p is Substantially fi shock, and assuming the occurrence of a shock while the base Id of the gene y Cylindrical with aforce component in the direction from left We ht 9 is n roW down from the body end to right as viewed in the drawing, then the weight rounded along its periphery e5 S 9 is caused to turn counterclockwise about a porpermitting movement of th t e We ght 9 tion of the periphery of its base 16 into the posiand the crank 3 relatively to each other, I protion shown in Fig. 2 until the head It of the rod v a sl p or w l connection between these it engages the side of the shoulder 2i opposite to parts. As shown, this connection comprises a t t Shown i Fig, 1, Thi movement of the substantially rigid member such as a rod 13 eX- 5 Weight 9 compresses the spring 22 and raises the tending 3 through an Opening provided rod generally upward thereby causing counterin flange 5 0 t arm 5 0f t Crank 3 and clockwise movement of the crank 3. This movethlollgh Openings and 17 p e in e ment brings the crank arm t into engagement s of the p 7 d in the We D with the trip arm 2 to prevent rotation of the trip t Y- To prevent e esc pe of the rod I3 40 shaft i in the tripping direction. As long as through these openings and also to determine the t shock force is maintained, the blocking a effective length of e end Connection, end tion thus directed is continued. While the force largements are provided on the rod in the form of acting n th weight 9 in consequence of a shock a head 18 and a nut ii), the latter being threaded causes it t move first to an offcenter position 011 the T001 and preferably of the p yp relatively to the cup I, as shown for example in In orde to permit the e try of the head IS on the Fig. 2, the weight subsequently rolls around the rod it! into the weight 9 so that the weight cannot inner n g i of t cup at b t t same n. slip off. the W g s provided Withasllhstahtially clination to the plane of the bottom surface of cylindrical opening 2i; somewhat larger in diamth cup, that to g rate about an axis 24 eter than the maximum diameter of the head I8. through the axial center of the rod Hi. This A 5 t e relative Size f the p ngs 20 and I! rolling or spinning action persists until the shock Where ey meet is such as to provide a retaining vibrations subside and therefore maintains a relas o l 3! for gement with the head It. tively constant restraining force which con- F0 maintaining the inverted pe d e t tributes substantially to the successful perform- 9 in a predetermined central shock susceptible ance of apparatus embodying my invention.

position in the cup 7 and ye p t g the de- Upon cessation of the shock, the spring 22 and sired movements o t e eight 9 and the crank 3 gravity take over to restore the weight 9 to the relatively to each other, I provide yieldable force central rest position, and the spring 22 returns the exerting means such as a resilient member 22. crank it to the initial position with the parts As shown, this member is a compression spring again positioned as shown in Fig. l.

positioned around the rod l3 between the lower From the foregoing, it will b obvious that any side of the cup '3 and the upper side of the flange force component of shock which tends to turn the $5 on the arm of the crank 3. This spring tends weight about any point of the periphery of its to maintain the weight 9 in its normal or rest base it will produce a tripblocking action in a position and th blocking element or crank 3 in similar manner.

its initial position, all as shown in Fig. 1, so that While I have shown and described my invention under normal conditions, that is, no shock, there in considerable detail, I do not desire to be limited is no interference whateverwi'th the trip shaft I to the exact arrangements shown, but seek to Consequently, there is no interference whatever cover in th appended claims all those modificawith the sensitivity of the setting of the circuit 7 times that fall within the true spirit and scope of breaker trip devices. Inasmuch as the restrainmy invention.

ing force on the arm 2 is largely dependent on What I claim as new and desire to obtain by the severity of the shock, a simultaneous fault Letters Patent of the United States is:

will in many cases produce suiiicient line disturb- 1. A shock responsive mechanism for preventance for the coincident tripping forces of the ing the false operation of a device on the occurm rence of shocks comprising a blocking element movable from an initial position into engagement with a part of the device to prevent a shock produced operation thereof and means for effecting said preventive movement of the blocking element comprising a support subject to shocks affecting the device, an inverted pendulum weight mounted on said support for substantially universal conic rotary movement relatively thereto in response to shock, a swivel connection between said weight and said element for permitting rotary movement of the weight relatively to the element, and yieldable force exerting means tending to maintain said weight in a predetermined central shock susceptible position on said 1 support and said blocking element in its initial position.

2. A shock responsive mechanism for preventing the false operation of a device on the occurrence of shocks comprising a relatively immovable cup subject to shocks affecting the device, a weight having a base portion seated in said cup in the rest position of the weight, said base portion and said cup being shaped to permit angular movement of the weight relatively to the cup, a crank positioned for angular movement from an initial position into engagement with a part of the device to prevent a shock produced operation thereof, a limited length slip connection, between said weight and said crank for effecting the blocking movement of the crank upon a predetermined angular movement of the weight relatively to the cup, and yieldable force exerting means between the cup and the crank tending to maintain the weight in its rest position and the crank in its initial position.

3. A shock responsive mechanism for preventing the false operation of a device on the occurrence of shocks comprising a relatively immovable cup subject to shocks affecting the device, a

weight having a base portion seated in said cup in the rest position of the weight, said base portion and said cup being shaped to permit angular movement of the weight relatively to the cup, a bell crank mounted so that upon a predetermined angular movement thereof from an initial position one arm of the crank engages a part of the device to prevent the operation thereof, a limited length slip connection between said weight and the other arm of said crank for effecting the blocking action of the crank upon a predetermined angular movement of the weight relatively to the cup, and resilient force exerting means between the cup and said other arm of the crank tending to maintain the weight in its rest position and the crank in its initial position.

4. A shock responsive mechanism for preventing the tripping of a circuit breaker on the occurrence of shocks comprising a pivotally mounted element movable in one direction from an initial position into engagement with the tripping mechanism of the circuit breaker to prevent the tripping thereof and means for effecting said blocklid ing movement of the blocking element compris- Y ing a cup subject to shocks affecting the circuit breaker, a weight having a base mounted in said cup for substantially universal movement of the weight relatively to the cup, means for effecting the blocking movement of said element upon a predetermined angular movement of the weight relatively to the cup comprising a rigid member extending loosely through an opening provided in said element and openings provided in said support and said weight, said member being provided with end enlargements exceeding the size of said openings for determining the effective length of the member, and a compression spring between said support and aid element tending to maintain the weight in a predetermined shock susceptible position and the blocking element in its initial position.

5. A shock responsive mechanism for preventing the tripping of a circuit breaker on the occurrence of shocks comprising a relatively immovable cup subject to shocks affecting the circuit breaker, a weight having a base portion seated in said cup in the rest position of the weight, said base portion and said cup being shaped to permit angular movement of the weight relatively to the cup, a bell crank mounted so that upon a predetermined angular movement thereof from an initial position one arm of the crank engages the tripping mechanism of the circuit breaker to block the tripping action thereof, a slip connection between said weight and the other arm of said crank for effecting the blocking action of the crank upon a predetermined angular movement of the weight relatively to the cup comprising a rigid member extending loosely through an opening provided in said other arm of the crank and openings provided in said cup and said weight, and enlargements on said member near the ends thereof exceeding the size of said openings for determining the effective length of said slip connection, and a compression spring around said member and between the cup and the other arm of said crank tending to maintain the weight in its rest position and the crank in its initial position.

6. A shock responsive mechanism for preventing the tripping of a circuit breaker on the occurrence of shocks comprising a relatively immovable cup subject to shocks affecting the circuit breaker, a weight having a base portion seated in said cup in the rest position of the weight, said base portion and said cup being shaped to permit angular movement of the weight relatively to the cup, a bell crank mounted so that upon a predetermined angular movement thereof from an initial position one arm of the crank engages the tripping mechanism of the circuit breaker to block the tripping action thereof, a slip connection between said weight and the other arm of said crank for effecting the blocking action of the crank upon a predetermined angular movement of the weight relatively to the cup comprising a rigid member extending loosely through an opening provided in said other arm of the crank and openings provided in said cup and said weight, and enlargements on said member near the ends thereof exceeding the size of said openings for determing the effective length of said slip connection, one of said enlargements being movable lengthwise of the member for varying the effective length of the connection, and a compression spring around said member and between the cup and the other arm of said crank tending to maintain the weight in its rest position and the crank in its initial position.

JOHN A. FAVRE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,158,753 Hansen May 16, 1939 2,306,974 Oestermeyer Dec. 29, 1942 2,409,115 Ellis Oct. 8, 1946 

